Patients with diabetes mellitus (DM) and peripheral neuropathy are at high risk for forefoot plantar ulcers and subsequent lower extremity amputation. Total contact casting currently is the most effective treatment for healing neuropathic plantar ulcers but ulcer recurrence is high (30-50%) when patients discontinue casting and resume walking. An equinus deformity (limited ankle dorsiflexion range-of-motion [ROM]) is associated with these recurrent ulcers. Although descriptive evidence indicates an Achilles lengthening procedure (which corrects the equinus deformity) can improve healing rates in chronic ulcers, there have been no controlled trials. The primary purpose of this study will be to conduct a randomized prospective controlled trial to determine if percutaneous Achilles lengthening and total contact casting is more effective than total contact casting alone to heal forefoot plantar ulcers. Secondary purposes are to determine the effects of casting and percutaneous Achilles lengthening on measures of impairments, functional limitations, and disability in patients with DM and peripheral neuropathy. The specific aims of this project are to determine the effect of the Achilles lengthening procedure on patients with DM, peripheral neuropathy, a forefoot ulcer, and an equinus deformity in regards to 1) Wound healing, 2) Impairments (dorsiflexion range-of-motion, plantar flexor muscle performance), 3) Functional Limitations (Physical Performance Test, Functional Reach, walking ability), and 4) Disability (SF36). The results will have important implications for prevention of wound infection and lower extremity amputation; and improvement in impairments, functional limitations, and disability in this group of high risk patients with chronic disease.